Emma Hannigan, best-selling Irish author of 13 books, extraordinary friend, mother, wife, and person died on Saturday.

She had fought breast cancer for 12 years in a highly publicized battle that had helped thousands of Irish women cope with the same disease. She leaves her husband and two young children behind.

Thousands flocked to buy her book All to Live For, documenting her battle with cancer. Afterward, she revealed all proceeds would go to breast cancer awareness.

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Hannigan knew she was about to pass and posted in late February that "time that I knew was borrowed must be given back soon, so it seems."

The cancer that she has held at bay for 11 years could not be held off any longer. She said, “My medical team has thrown everything but the kitchen sink at this fight but all avenues have now been exhausted.

"To say that I am heartbroken doesn’t begin to cover it."

Irish author Emma Hannigan. Credit: Facebook

Irish author Emma Hannigan. Credit: Facebook

In 2005, the mother-of-two was told she carries the BrCa1 gene, which increases here risk of developing breast and ovarian cancer. She had her breasts and ovaries removed in 2006 but still developed cancer 10 times over the last decade, the Irish Examiner reports.

On her website, the 45-year-old thanked her fans for their support through the years.

"I’ve gained such strength from all of you. We’ve shared tips and hints and stories over the years. For all of it – thank you.

"Thank you for taking my hand when I needed it most and for posting all sorts, from doggy snaps to moggy pics and the rest.

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"We’ve made a great team."

She went on to say that her love for her husband Cian, son Sacha, daughter Kim, family, friends, and readers is “all that matters now.”

President Michael D Higgins paid fulsome tribute on Saturday evening. “Emma Hannigan leaves a lasting legacy not only through her work as a much-appreciated author but also through her exemplary courage in dealing with terminal illness. She will be remembered as a powerful advocate for Breast Cancer Ireland, a great cause worthy of all of our support. To her husband, Cian, her son, Sacha, and daughter, Kim, and to her wider family and circle of friends, Sabina and I send our deepest sympathies.”